Patent GB-670580-A (GB)
Title: Manufacture of new imidazolines
IPC: C07D417/06
Filed: 1948-02-12
Abstract: Phenthiazinyl - methyl - imidazolines of the formula <FORM:0670580/IV (b)/1> and substitution derivatives thereof are prepared by reacting (1) a phenthiazine or N-metal derivative thereof with a reactive ester of a 2-oxymethyl-imidazoline, or (2) a phenthiazine-N-acetic acid with the appropriate alkylene diamine.  The benzene nuclei may be substituted by alkyl (e.g. methyl, ethyl), hydroxy, etherified or esterified hydroxy (e.g. methoxy, ethoxy, propyloxy, butyloxy, benzyloxy, acetoxy or benzoyloxy), amino or nitro groups or by halogen atoms.  The imidazoline nucleus may contain alkyl substituents, e.g. methyl, ethyl or propyl.  In method (1), a halide or alkyl or aryl sulphonate ester of the imidazoline (preferably as salt) may be reacted with the phenthiazine, or N-sodium derivative if no free hydroxy group is present.  A diluent and/or condensing agent may or may not be present.  For method (2), the reactive derivative may be an imido-ether, imido-halide, thioamide, thio - imido - ether, amide, ester, amidine or nitrile.  The derivative may be formed in situ, e.g. by using a nitrile with hydrogen sulphide, carbon disulphide, phosphorus pentasulphide or iron, aluminium, ammonium sulphide with water.  The alkylene diamine may be ethylene diamine or a C- or N-substitution derivative thereof, preferably in the form of a mono-salt; N : N1-ethylene urea is suitable.  A diluent and/or condensing agent may or may not be present.  The reaction may be carried out in stages by first forming the acyl derivative of the diamine and then heating this with a dehydrating agent. The products may be obtained as salts in the reaction mixture, or if not may be converted into salts with acids, e.g. hydrohalic, sulphuric, phosphoric, acetic, methane sulphonic or toluene sulphonic.  Examples show the preparation of 2 - (N - phenthiazinyl - methyl) - imidazoline by both methods and of 2-(21-methoxy-phenthiazinyl - methyl) - imidazoline by method (1).  In a further example, hydrolysis of the latter occurs during the reaction to give 2-(21-hydroxy-phenthiazinyl-methyl)-imidazoline.  N - Phenthiazinyl - acetonitrile is obtained from phenthiazine, formaldehyde and hydrocyanic acid.  Specifications 514,411 and 608,295 are referred to.  The Specification as open to inspection under Sect. 91 (4), refers to analogous compounds where the -CH2- linkage between the nuclei in the above formula is replaced by any alkylene group; these are prepared by methods (1) and (2) above, using the appropriate starting materials.  It is also stated that acyloxy groups in the products may be hydrolysed to free hydroxy groups and that aralkoxy groups may similarly be split by catalytic hydrogenation.  Free hydroxy groups in the products may be esterified, e.g. with acetic, propionic, butyric or benzoic acid, or converted into alkyl or aminoalkyl ethers.  The Specification also contains the subject-matter of Specification 670,610, and the information in the three preceding sentences is also applicable to the phenoxazines of Specification 670,610.  This subject-matter does not appear in the Specification as accepted.